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Vector scope
: a test instrument for displaying color hue and saturation in a video signal used to aid in color
correction.
Waveform monitor
: a test instrument which shows a graphical representation of the luminance levels of the
video waveform, used, in conjunction with a vectorscope, as an aid in color and image correction
and video system set up.
White balance
: the adjustments of color circuitry in a video camera to produce an image with balanced white
and color components, where the white component has a specific color temperature or color cast.
Y/C
: the separate processing of the light (luma or Y) and chroma (C) parts of a video signal for higher image
quality than composite video; a.k.a. S-video.
Y.U.V.
: one of the formats of component video; one of the descriptions of component color space, in this
case Y (luminance), and U (blue), and V (red) hue saturation.
Zoom
:
1)
to change the size of an area selected for display to provide either a more detailed view or more
of an overview;
2)
for a camera shot, to change the distance relationship between the camera and subject.
Tech Notes
Books are written about many of the topics below, large and complex books. Look for them if you want more
information than what we have presented here. What we want to do here is to provide a bit more in depth
information, deeper background, on some relevant topics, and give you a framework for further technical
investigations.
Video Standards, Formats, and Quality
Video standards refer to the broadcast and/or viewing systems; they are specific to certain regions of the
world. In the US, Canada, and Japan, the analog standard is NTSC (which stands for National Television
Standards Committee, the organization that formalized the standard). In Europe (except France and Eastern
Europe), the standard is PAL (phase alternate line). In France, the Middle East, and most of Eastern
Europe, SECAM (sequential coleur avec mémoire) is the standard.
Why is this important? In part, because each standard requires compatible monitors, cameras, VCRs,
projectors, and switchers. The signals are electronically different from format to format, and so cannot
interoperate unless the equipment is specifically designed to be multi-standard.
Within each standard are multiple formats - different systems of recording video onto different types of
medium.
At the lowest quality and cost level is VHS, a composite form of video, meaning the chroma (color) and luma
(lightness) bits of information are electronically mashed together into one signal: convenient, inexpensive,
and very much of a compromise of image quality. Colors are not reproduced especially brilliantly, but firsts
generation quality is usually high enough for accurate viewing. 8mm is the similar format but recorded on
narrower tape. Plugs for composite video can be either RCA or BNC.
Y/C, or S-video, is so named because the chroma (C) and luma (Y) information is kept separate in the signal,
processed separately, and even transmitted separately. The result of this separation is far greater color
fidelity and detail. S-video can be recorded onto specially formulated VHS (S-VHS) or 8mm (Hi8) tapes.
There is a special 4 pin connector for Y/C signals.
There are many variations of 3 wire analog component video: Betacam, MII, etc. They are all relatively (but
not completely) similar ways of describing a color space like Y/C, except that the C component is broken into
2 signals, for maximum color reproduction, fidelity, and detail. You may see the signal described as RGB,
YUV, YCC, Y B-Y R-Y. Usually cables with BNC connectors are used for component signals.
The point of all this technical information is ultimately to help you to make high quality video: video that looks
good and serves the purpose for which it is made. But how do we know if the video is of high quality? And
what does that really mean?
There are certain technical standards that video must meet simply in order to be viewable on a monitor. And
beyond that fairly cut and dried realm is the area of aesthetics. Which leaves us with the notion that most
discussions of video quality are relative, in the sense that there is a context, a purpose to which definitions of
quality level relate. For example, a video that looks acceptable on an inexpensive television set might look
absolutely horrible on a high end video monitor. Is this because the expensive monitor cannot display the
video properly? No, probably not. In fact, the reverse is true: the inexpensive monitor doesnt show enough
